Device for bending tubes



P. CATUCCI AIJD L. D. NADEL. DEVICE FOR BENDWG TUBES.

APPLXCATION FILED Nov. 20, 1918.

' 1,379,168, Patented May 24 1921.

4 SHEEIS-SHEET I.

P. CATUCCI AND L. D. NADEL.

DEVICE FOR BENDING TUBES.

APPLICATION FILED NOV= 20, ms.

L379, 168, Paw-lied y 24, 1921.

4 SHEEIS-SHEET lgtyggjizwwziora P. CATUCC! AND L. D. NADEL.

DEVICE FOR BENDING TUBES.

APPLICAHON FILED HOV- 20, I918- Patented May 24, 1921.

4 SHEETSSHEET 3- VrIIIIAI/I/QI IAJIIZFZ VWMWH .lllll/ /I/IA P. CATUCC] AND L. D. NADEL.

DEVICE FOR BENDING TUBES.

APPLICATION mm NOV, 20. 1918.

1 ,3? 9, 1 68. Patented May 24, 192i.

4 SHEETSSHEET 1: %& I fizzle/2307's UNITED STATES PATENT OFFICE.

PLINY GATUCCI AND LOUIS D. NADEL, OF NEWARK, NEW JERSEY, ASSIGNORS, IBY MESNE ASSIGNMENTS, TO HARRIMAN NATIONAL BANK OF THE CITY OF NEW YORK, TRUSTEE.

DEVICE FOR BENDING TUBES.

Specification of Letters Patent.

Patented May 24, 1921.

Application filed November 20, 1918. Serial m 263,301.

To all whom it may concern:

Be it known that we, PLINY CATUOCI, a citizen of the United States, and, a resident of Newark, in the county of Essex and State of New Jersey, and LoUIs D. NADEL, a citizen of the United States, and a resident of Newark, county'of Essex, and State'of New Jersey, have invented a certain new and useful Device for Bending Tubes, of which the following is a-specificatio n.

The invention relates to apparatus forming metal tubes into simple or complex bends of any radius.

The objectsof the invention are to provide a machine in which tubesof even the thinnest material may be bent in any shape tions may be expeditiously carried out and waste eliminated.

A further object of the invention is the provision of means of the character herein described, which are simple in operation and construction, and thoroughly reliable and efiicient in its purpose and operation.

With these and other objects in view to be more fully set forth hereinafter, the invention consists in the novel construction, combination of elements, and arrangement of parts which will be exemplified in the operation and construction hereinafter described in the specification and illustrated in the accompanying drawings considered together or separately.

The inventive ideainvolved is capable of receiving a variety of mechanical expressions, one of which for the-purpose of illustrating the invention, is shown in the accompanying drawmgs. I

for

The invention will be first described in connection with the accompanying drawings, illustrating one embodiment of the inratus with the parts in extended position,

Fig. 4 is a similar view showing the parts in retracted position;

Fig. 5 is a detail section on the line 5-5 of Fig. 3;

Fig. 6 is a detail section on the line 6 -6 of Fig. 4;

Fig. 7 is a transverse section of the fluid regulator, the section being taken on the line 77 of Fig. 8;

F ig'. 8 is a longitudinal section of the same taken on the line 8-8 of Fig. 7;

Fig. 9 is a plan view partly in section of the pilot valves; and

Fig. 10 is a section on the line 10-10 of Fig. 9.

The process of bending the tubes at present in use, requires at least two separate and different operations, for which at least two different machines are required. The first operation consists in drawing or pulling the tube in its true tubular form during this operation, the strains to which the metal is subjected result in the formation of harmful and disfiguring wrinkles or cracks in the tube. Subsequent operations are, therefore, necessary to remove these defects; their results, however, are really superficial, as it is practically impossible to remove or eliminate wrinkles or cracks after they have once been formed and allowed to set in the metal. As a result, extensive and costly polishing and buffing operations are required to make the tube at least presentable in appearance, though the strength and molecular integrity of the tube are hopelessly impaired.

The method of pulling the tube in the bending operation causes the metal of the tube on the outside of the bend to become thin in proportion to the sharpness of the bend. Often this part of the bend becomes so thin as to render the tube unfit for any commercial use. At times even the strain causes complete rupture of the metal on the outside of the bend, necessitating the scrapping of the tube with the accompanying Waste of material and labor.

Pulling the tube, necessitates the gripping of one endof the tube in some form of chuck. V The portion of the tube gripped is usually scored or otherwise mutilated and must therefore be removed from the rest of the tube and scrapped. I

The machine which is the subject of the present invention, bends tubes by pushing them through a form or-die of the required shape, at the same time pushing a series of balls through the interior of the tube in I the same direction in which the tube is bemg pushed but at a speed usually considerab y faster. The balls passing through the tube keep it constantly distended and in perfect tubular form, for the speed of the balls is so adjusted that there is no opportunity for wrinkles or cracks to develop. The friction of the balls against the interior of the tube aids in forcing the tube through the die, the balls being a snug fit in the tube. As the tubes are pushed through the die instead of being pulled, there is no possibility of drawing the'tube so as to leave one portion any thinner than another. The finished bend therefore, is removed from the die at the end of the one bending operation absolutely smooth inside and out and with its original appearance, strength, and perfect tubular form unimpaired.

The machine with which these results have been obtained operates on the hydraulic principle, though a machine operated pneumatically, or as a screw press, toggle press, rack press, crank press, or any combination of the above or with any other mechanism for exerting pressure operating with either a continuous or an intermittent motion, would have equally good results.

The apparatus comprises a frame-work of any desired form, in which is supported a main single acting cylinder 1, the head being provided with a tubular extension 2 which extends into the cylinder, whereby the latter is made annular. Coiiperatingwith the cylinder 1 is an annular piston 3 which forms an auxiliary single acting cylinder 4,

tremities are attached to the frame with which cooperates a piston 5.. The cylinder 1 has an inlet port 6 in one side thereof, and the bore of the tubular extension 2 forms the inlet of the cylinder 4,

The cylinder 1 is provided with a pair of oppositely disposed wings, each carrying a rod 7 which extends from said cylinder to an abutment 8 at the opposite end of the machine. The piston-cylinder 34 is provided with ears which slide over studs 9 carried by the cylinder 1. The studs carry nuts 10 which act as stops to arrest the outward movement of the piston cylinder. The outer extremity of the cylinder 4 carries a cross head 11, movable on the rods 7, 7, and the outer extremityof the piston carries a similar cross-head 12, also slidable on the rods site the tube 16.

Carried by the main frame, and in. prox imity'to the abutment 8 is the die in which the bend is to be made. This die comprises two parts 19 and 20, each of which has a semi-cylindrical recess of the angular form. The parts 19 and 20 are clamped together by means of a screw 21. and are so arranged that the bore of the die is in axial alinement with the plunger 15 and tube 18. That end of the recess in alinement with the plunger is counterbored to receive the end of a tube 22, the bore of which is of somewhat greater diameter than the exterior of the tube to be bent; I

A trough 23 is carried on the machine in line with theplunger 15, and has a spout 24 which leads to the free extremity of the tube 16, which is preferably beveled as shown. A gate 25 is carried by the trough 23. A receiver 26 is placed below the outlet of the die.

Pivoted to each end of the cross-head 12 is a lever 27 to each end of which is pivoted a link 28. The opposite ends of the links of each lever 27 are connected by a bar 29, and the center of each bar is pivoted to the long arm of a bell-crank lever 30,

the short arm of which is secured to the lower ends of two springs 31; the other exabove the apparatus.-

In connection with the device above described, there are provided means for regulatlng the flow of the actuating medium? In the present apparatus the actuatingmedlum is a fluid, such as oil. The regulator comprises a cylinder 32 having an inlet port 33 and two outlet ports 34 and 35, one

inder 32 are each provided with a pilot valve 39, connectingwith a pipe 30, leading to the intake of the pump (not shown). ach of the valves 39 has a pin 41 which is moved to open the valve, by means of a spring 42. A oke 43 engages the head of each pin, an said yoke is carried on a screw 44 engaging a nut 45. The squared outer extremity of the screw carries a lever 46 which is connected by a pitman 47 to a lever 48. When the lever is thrown in one direction, the valves 39 are closed, and when moved in the opposite direction the said valves are opened by the springs 42.

Within the bore of the cylinder 32 is mounted a pistonvalve 49 by means of which the inlet 33 is always open to its fullest extent, and which may be moved to regulate the extent of the outlet openings 34 and 35. The piston valve is so arranged that as one outlet is diminished in extent the other is correspondingly increased, and at no time are both outlet openings entirely closed. The valve 49 is carried on a rod 50 which extends through stufiing boxes at both ends of the cylinder. One end of the rod is attached to a spring which moves the piston valve in one direction. The opposite end of the rod carries a grooved pulley 51, around which extends a chain or cable 52. The cable 52 extends around and is secured to a pulley 53 secured to a shaft-54 journaled in the base 55, on which the cylinder 32 is mounted. Secured to the shaft 54 is a double grooved pulley 56, to which a cable 57 is attached. A second cable 58 is also attached to the pulley 56 and wound thereon in the direction opposite to that in which the cable 57 is wound. The cable 57 is provided with .a turn-buckle 59 and is attached to the crosshead 11. The cable 58 is attached to a spring 60. i

The cable 52 extends around and is secured to a pulley61'which carries a smaller pulley 62, and a cable 63 is anchored to and wound around said pulley 62. The cable is provided with a turn-buckle 64, and is attached to the cross-head 12.

The operation is as follows The tube '65 to be bent is placed in the tube 22 and one end of the latter is inserted in the counterbore of the die. The elements of the machine are in the positions shown in Figs. 4 and 6.. The tube 16 is now filled with a plurality of hardened steel balls 66 of a diameter sufiicient to make a close fit with the bore of the tube to be bent. The halls form a movable coil for the tube. The

halls will fill the tube 16, the nut '17,the tube 18, which latter is in position to engage the tube 65, which is also filled with the balls.

The pump (not shown) will be started, andthe fluid will circulate in a closed circuit through the pipe 36, port 33, ports 34 and 35, pipes 37 and 38, valves 39 which are open, and pipe 40 back to the pump. The operator will now throw the lever 46 to advance the screw 44 in the nut 45, and

the pins 41 will now be seated, and the fluid will enter the cylinders 1 and 4 through the pipes 37 and 38. If the piston valve 49 be properly set, the port 34 will be opened to a greater extent than the port 35, and the piston 5 will be driven forward at a much higher rate than will the piston 3.

The tube 18 being connected to the piston 3, will slowly force the tube 65 into. the die and bend it to the shape of the recess therein. At the same time the plunger 15 "will drive the balls 66 forward through the tube being bent, but at a much higher rate of speed than that attained by the tube 18.

The frictional engagement of-the balls with the interior of the tube 65 will assist in forcing the said tube through the die, and will, because of rapidity of the travel of the balls, prevent wrinkling, creasing, collapsing, and breaking of the tube, and the exterior and interior surfaces of the bent tube will be as perfect as those surfaces were before the bending operation. I

As the balls are passing through the tube 65, they drop into the receiver 26, and the operator replaces them in the trough 23, to be used in the next tube to be bent. The screw 21 is backed up, the die members are separated, and the bent tube is removed, and the balls therein are deposited in the trough. The operator in the meantime has thrown the lever 46 to back the screw 44 out of the nut 45, the springs 42 will insert the valves 39, the fluid in the cylinders will descend in the pipes, and the fluid will be pumped in the closed circuit as before.

During the bending operation, the movement of the cross-head 12 will rotate the pulleys 61 and 62 in the clock-wise direction, and the movement of the cross-head 11 will rotate the pulleys 56 and 53 in the anti- -clock-wise direction, and if the speed of the should vary from the ratio that the diameter of the pulley 56 bears to the pulley 53, the pulley 51 will be moved away from or toward the cylinder 32, as the piston 5travels too fast or too slow. The movement of the pulley 51 will move the piston valve to reduce the size of the port 34 and increase that of the port 35, or vice-versa, as the case may -By this method the be, until the speed ratio of the pistons is exactly that of the diameter ratio of the pulleys 56 and 53.

When the valves 39 are opened, the springs 31 will return the parts to the positions shown in Fig. 4, and expel the fluid from the cylinder, and the spring 60 will. rotate the pulleys of the differential backward, and take up the slack in thecables 57 and 63.

In some situations, it may be deslrable to drive the balls some distance before the movement of the tube is begun. In this case the turn-buckle 39 is loosened to make slack in the cable 57 and the plunger 15 will be driven forward some distance before the differential is brought into play. v When tubes of different diameter are to be bent, new dies, a new tube 22, new tube 18, new nut 17, new tube 16, and new balls are employed. The same plunger may be used, or if the new tube be of larger dlameter, a smaller plunger Wlll be used for smaller tubes. I

For performing rapid work, 1t 1s desirable to employ balls'of different dlameters. The work balls will have a' close fit with the bore of the tube to be bent, and the follpwefballs for use to drive the work balls through the tube may be somewhat smaller. follower balls may be more easily removed from The surplus balls are retained in the by the gate 25.

trough The fluid regulator is not claimed in this application, but is the subject matter of Patent No. 1,350,782 granted to us upon application Serial No. 263,302, filed November 20, 1918.

In accordance with the provisions of the patent statute, we have described the principle of our invention together with the apparatus which we now' consider to represent the best embodiment thereof, but we desire it understood that our invention is not confined to the particular form of apparatus herein shown and described, the same being merely illustrative, and that the invention can be carried out in other ways without departing from the spirit of our invention, and, therefore, we claim broadly .the right to employ all equivalent instrumentalities coming within the scope of the appendedv claims, 'an'd'by means of which objects of our invention are attained, and the new results accomplished, as herein set forth, as it is obvious that the particular embodiment herein shown and described is only one of many that can be employed to attain these objects and accomplish these results.

Having now described our invention, what we claim. and desire to secure by Letters Patent is as follows 1. An apparatus for bending tubes, which the bent tubes.

comprises a cylinder, a piston therein, means carried by the piston for engaging a tube and pushing the same into a die, a second cylinder, a piston cooperating with said second .cylinder, and means carried by the second piston for'pushing a series of balls through the tube at a higher rate of speed.

2. An apparatus for bending tubes, which comprises a cylinder, a piston therein, means carried by the piston for engaging a tube and pushing the same into a die, a second cylinder, a piston coiiperating with said second cylinder, and means carried by the second iston for pushing a series of balls throng the tube, at a higher rate of speed than the travel of the tube.

3. An apparatus for bending tubes, which comprises a cylinder, a piston therein,

means carried by the piston for engaging a tube and pushing the same into a die, a second cylinder, a piston cooperating with said second cylinder, means carried by the second piston for pushing a series of balls tube and pushing the same into a die, a second cylinder, a piston cooperating with the same, means carried by the second piston for pushing a series of balls through the said tube simultaneously with the travel 0 the latter and in the same direction but at a higher rate of speed, common means for moving the pistons, and means operated by the movements of the pistons for regulating the speed thereof.

5. An apparatus for bending tubes, which comprises a cylinder, a piston therein, means carried by the piston for engaging a tube and pushing the same into a die, a second cylinder, a piston. cooperating with the same, means carried by the second piston for pushing a series of balls through the said tube simultaneously with the travel of the latter and in the same direction but at a higher rate of speed, common means for moving the pistons, and means operated by the movements of the pistons for automatically regulating the speed thereof. v 6. An apparatus for bending tubes, which comprises .a cylinder, a piston therein, meanscarried by the piston for engaging a tube and pushing the same into a die, a second cylinder, a piston .coiiperating with the same, means carried by the second piston for pushing a series of balls through the said tube simultaneously with the travel of the latter and in the same direction but at a higher rate of speed, common means for movlng the pistons, and difierential means operated by the movements of the pistons tons and cylinders and mechanism for con- 10 for automatically regulating the speed thereof.

7. An apparatus for bending tubes, compressing means for pushing a tube through a die, and means for ushing a core through the tube, and means r moving each of sad aforesaid means at different rates of speed,

* said last mentioned means comprising pistrolling them.

This specification signed and witnessed thi 31st day of October 1918.

1 LINY CATUGCI.

LOUIS D. NADEL.

Witnesses: JOHN L. LOTSOH, MORTIMER LANZIT. 

